Biological diversity refers to all living organisms, their genetic material and the ecosystems of which they are a part. It is usually described at three levels: genetic, species, and ecosystem. Biological diversity is the cornerstone of sustainable agriculture and world food security. The loss of cultural diversity (including languages) and traditional knowledge -- of farm communities and indigenous cultures -- is intricately linked to the loss of biological diversity. Indigenous peoples and farming communities are the creators, custodians and continuing innovators of biological knowledge and resources. The UN Convention on Biological Diversity (often referred to as the CBD or Biodiversity Convention) is a legally-binding framework for conservation and sustainable use of biodiversity.